title: Hemianopic and quadrantanopic field loss, eye and head movements, and driving.
abstract: OBJECTIVE
  To compare eye and head movements, lane keeping, and vehicle control of drivers with hemianopic and quadrantanopic field defects with controls, and to identify differences in these parameters between hemianopic and quadrantanopic drivers rated safe to drive by a clinical driving rehabilitation specialist compared with those rated as unsafe.
  
  
  METHODS
  Eye and head movements and lane keeping were rated in 22 persons with homonymous hemianopic defects and 8 with quadrantanopic defects (mean age, 53 years) who were ≥6 months post-injury and 30 persons with normal fields (mean age, 53 years). All were licensed to drive and were current drivers or aimed to resume driving. Participants drove a 6.3-mile route along non-interstate city roads under in-traffic conditions. Vehicle control was assessed objectively by vehicle instrumentation for speed, braking, acceleration, and cornering.
  
  
  RESULTS
  As a group, drivers with hemianopic or quadrantanopic defects drove slower, exhibited less excessive cornering or acceleration, and executed more shoulder movements than the controls. Those drivers with hemianopic or quadrantanopic defects rated as safe also made more head movements into their blind field, received superior ratings regarding eye movement extent and lane position stability, and exhibited less sudden braking and drove faster than those rated unsafe.
  
  
  CONCLUSIONS
  Persons with hemianopic and quadrantanopic defects rated as safe to drive compensated by making more head movements into their blind field, combined with more stable lane keeping and less sudden braking. Future research should evaluate whether these characteristics could be trained in rehabilitation programs aimed at improving driving safety in this population.
authors.affiliation: School of Optometry, Queensland University of Technology, Brisbane, Australia. j.wood@qut.edu.au
authors.forename: Joanne M
authors.initials: JM
authors.lastname: Wood
authors.forename: Gerald
authors.initials: G
authors.lastname: McGwin
authors.forename: Jennifer
authors.initials: J
authors.lastname: Elgin
authors.forename: Michael S
authors.initials: MS
authors.lastname: Vaphiades
authors.forename: Ronald A
authors.initials: RA
authors.lastname: Braswell
authors.forename: Dawn K
authors.initials: DK
authors.lastname: DeCarlo
authors.forename: Lanning B
authors.initials: LB
authors.lastname: Kline
authors.forename: Cynthia
authors.initials: C
authors.lastname: Owsley
mesh_terms: D001334:Automobile Driving; D005133:Eye Movements / Q000502:physiology*; D019416:Head Movements / Q000502:physiology*; D006423:Hemianopsia / Q000503:physiopathology*; D006801:Humans; D008875:Middle Aged; D014741:Video Recording; D014792:Visual Acuity / Q000502:physiology; D014794:Visual Fields / Q000502:physiology*